Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities:
Net income	$ 76,348	$ 101,926
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit loss expenses	27,825	10,085
Specific reserve, other real estate owned	537	88
Depreciation of bank premises and equipment	14,299	14,013
Gain on sale of bank premises and equipment	(155)	(194)
Loss (gain) on sale of other real estate owned	13	(639)
Accretion of investment securities discounts	(241)	(186)
Amortization of investment securities premiums	14,877	8,240
Investment securities transactions, net	5	10
Unrealized gain on equity securities with readily determinable fair values	(99)	(190)
Stock based compensation expense	395	504
Losses (earnings) from affiliates and other investments	203	(290)
Deferred income taxes	(14,861)	764
Increase in accrued interest receivable	(11,064)	(1,153)
(Decrease) increase in other assets	244	(25,589)
Increase in other liabilities	28,186	18,028
Net cash provided by operating activities	136,512	125,417
Investing activities:
Proceeds from maturities of securities	1,075
Proceeds from sales and calls of available for sale securities	18,920	60,695
Purchases of available for sale securities	(458,184)	(380,095)
Principal collected on mortgage backed securities	753,483	317,822
Net increase in loans	(598,176)	(316,959)
Purchases of other investments	(25,329)	(35,766)
Distributions from other investments	26,688	56,181
Purchases of bank premises and equipment	(4,593)	(14,409)
Proceeds from sales of bank premises and equipment	786	1,793
Proceeds from sales of other real estate owned	3,625	1,470
Net cash used in investing activities	(281,705)	(309,268)
Financing activities:
Net increase in non-interest bearing demand deposits	870,839	100,067
Net increase in savings and interest bearing demand deposits	290,105	36,089
Net increase (decrease) in time deposits	48,745	(4,043)
Net increase in securities sold under repurchase agreements	150,559	11,199
Net decrease (increase) in other borrowed funds	(190,092)	102,711
Redemption of long-term debt		(25,774)
Purchase of treasury stock	(48,737)	(128)
Proceeds from stock transactions	288	874
Payments of cash dividends - common	(35,128)	(32,822)
Net cash provided by financing activities	1,086,579	188,173
(Decrease) increase in cash and cash equivalents	941,386	4,322
Cash and cash equivalents at beginning of period	256,820	316,797
Cash and cash equivalents at end of period	1,198,206	321,119
Supplemental cash flow information:
Interest paid	23,555	28,602
Income taxes paid	370	27,864
Non-cash investing and financing activities:
Net transfers from loans to other real estate owned	2,234	22,281
Establishment of lease liability and right-of-use asset		$ 6,171
Net transfers from bank premises and equipment to other assets	$ 4,260